[Disaster preparedness] Three levels of disaster preparedness

[Disaster preparedness] Three levels of disaster preparedness

Operation and Maintenance YouthO&M Youth

According to the recovery goals and the required cost input, disaster preparedness can be roughly divided into three levels. The figure can be represented by three nested concentric circles. From data-level disaster recovery, application-level disaster recovery to business-level disaster recovery, the level of business recovery is gradually increasing, and the required investment costs also increase accordingly.

Three levels of disaster preparedness

Disaster recovery level data level

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Data-level disaster recovery emphasizes data backup and recovery. Data-level disaster recovery, including data replication, backup, and recovery, is the basis of all disaster recovery work. In the process of disaster recovery and recovery, data recovery is the lowest level. For example, the data must be complete and consistent before the database can be started, and then the application can be started. After the application server takes over, the network can be switched.

This process needs to be strictly implemented to ensure the smooth switchover of disaster recovery. One of the important factors is why many applications fail during the switching process.

The focus of data-level disaster recovery is on data, that is, it can ensure that users' original data will not be lost or destroyed after a disaster occurs. Lower-level data-level disaster recovery can be achieved by manually saving the data that needs to be backed up to a remote location, such as regularly transporting the backup tape/hard disk to a remote location for storage.

Higher-level data disaster recovery solutions rely on network-based data replication tools to achieve asynchronous/synchronous data transmission between the production center and the disaster recovery center, such as the use of disk array-based data replication functions (database-based replication methods can be separated For real-time replication, timed replication and store-and-forward replication).

Disaster recovery level application level

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Application-level disaster recovery emphasizes the takeover of specific functions of applications, and it provides a higher level of business recovery capability than data-level disaster recovery. At the same time, it is also the foundation of business-level disaster recovery. Only when specific applications are restored can subsequent businesses be carried out effectively.

Application-level disaster recovery is to duplicate application processing capabilities on the basis of data-level disaster recovery, that is, to build a set of identical or similar support systems in remote disaster recovery centers. The support system includes a data backup system, a backup data processing system, and a backup network system.

Application-level disaster recovery requires the ability to provide application takeover, that is, in the event of a failure in the production center, the application can be taken over in the disaster recovery center, thereby minimizing system downtime and improving business continuity.

Disaster recovery level business level

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Business-level disaster recovery is the highest level of disaster recovery construction. If data-level disaster recovery and application-level disaster recovery are within the scope of IT systems, business-level disaster recovery is based on the above two levels of disaster recovery. It is also necessary to consider business factors other than the IT system, including alternate office space, office personnel, etc., and business-level disaster recovery usually has higher requirements for the IT system that supports the business (RTO is at the minute level).

For normal business, IT system guarantee is not enough. When a major disaster occurs, the user's original office space will be destroyed. In addition to the original data and the original application system, the user needs the staff to be able to conduct business normally in a spare workplace. In fact, business-level disaster recovery also pays attention to the backup of the business access network. It not only considers the service provision capability of the supporting system, but also considers the access capability of the service user and even the processing capability of the backup staff.